Lipofibromatous hamartoma of the median nerve: A case report

Lipofibromatous hamartoma of the median nerve: A case report
ABSTRACT
Lipofibromatous hamartoma is a rare and slow growing benign fibro-fatty tumor. It is characterized by the proliferation of mature adipocytes within the epineurium and the perineurium of the peripheral nerves. In the upper extremity, it most commonly affects the median nerve. Median nerve involvement commonly leads to pain, numbness, paresthesia and carpal tunnel syndrome. This article presents a case of lipofibromatous hamartoma in an 8-year-old child followed by a discussion of the epidemiology, diagnosis, imaging details and treatment options for this condition.
CASE REPORT
An 8-year-old Caucasian male presented to an outpatient orthopaedics center in 2011 for evaluation of a mass-like protuberance in the palmar aspect of his right hand (figure1). His parents noted that this mass was present since infancy but had been increasing in size over the past 2 years. Although asymptomatic at the time of presentation, history revealed two instances of numbness and tingling in his right hand over the past two years.
Physical exam revealed a soft non-mobile mass starting at patient’s distal forearm extending toward the 2nd and 3rd digits and ending distal to patients thenar crease. The area was non-tender and sensation of light touch was intact. . His median, radial, ulnar, anterior and posterior interosseous nerves were all intact. He had a +2 radial pulse and a brisk capillary refill. There was full range of motion in all fingers and no neurovascular deficit was noted.
A magnetic resonance imaging (MRI) test obtained May 2012 (figure 2) confirmed lipofibromatous hamartoma (LFH) of the median nerve. The mass measured 2.0 x 1.0 cm in transverse by anteroposterior dimensions, with 12 cm proximal-distal extension. Local mass effect and crowding in the region of the carpal tunnel was noted on imaging.
In March 2013, the patient presented again with complaints of worsening pain in his right hand once or twice a week in his thumb and thenar eminence. Squeezing or grasping activities like writing and focal compression of the mass aggravated the pain. Rest quickly resolved the discomfort. The patient noted no numbness, tingling or weakness in his right hand. Repeat MRI was obtained in April 2013 (figure 3). In comparison to prior imaging the mass lesion had grown to the following parameters: 2.4 cm x 1.2 cm in transverse by anteroposterior dimensions, with 12 cm proximal-distal extension.
Surgical intervention was not recommended at this time, given significant morbidity and patients minimal symptoms. Patient was encouraged to modify his activities, such as the way he holds a pencil or other objects or to try and alleviate pressure over this area. Otherwise the patient was told to continue observation and return to clinic if any new symptoms should arise. He was scheduled to have a one-year follow-up with a repeat MRI.
DISCUSSION
Lipofibromatous hamartom